Pachyseius crymophilus sp. nov. is described and illustrated based on specimens collected in an alpine meadow habitat in the Făgăraş Mountains, the Carpathians, Romania. It is closely related to Pachyseius strandtmanni Solomon, 1982 by the form and sculpture of idiosoma, the setae Jv3 placed on soft integument off the ventrianal shield, the fragmentation and arrangement of shields and sclerites of the peritrematal-podal-sternal complex, the hypertrophy of some poroids, and the setation of lateral and opisthogastric soft integument. A new identification key to world species of the genus Pachyseius is provided.